Electrical control system



1 Jan. 19, 1937. w. w. STUART 2,068,283

ELECTRICAL CONTROL SYSTEM Filed Jan. 28, 1936 Patented Jan. 19, 193? messes T OF The object of my invention is to provide in a cooling and heating system, having heating means and cooling means, a control structure including a summer-winter thermostat and an- 5 ticipating heater means associated with the ther mostat to hasten the action of the thermostat for stopping the operation of one controlled means and to hasten the action'oi the thermostat for starting the operationof the other controlled 10 means.

Another object is to provide in such a system means for varying the action of the anticipating heater.

Still another object is to provide in such a 18 system, means for cutting out the anticipating heater" when certain conditions exist.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of 2'0 my control system, whereby the objects contemplated are attained, as hereinafter more fully pointed out in my claims, and illustrated in the accompanying drawing, in which:

The single figure sets forth diasrammaticaliy 2s a heating and cooling system in which my invention is employed.

There is a very definite trend at the present time toward the installation oi combination heating and cooling means for residences and various 30 business places. Such installations have heating means, such as oil burners. and cooling means such as refrigeration equipment. In such syssummer cooling, the anticipating heater'causes a problem to arise. If left in the circuit, it then functions, not as an anticipating heater, but as'a delaying heater, and serves to lengthen the operation period of the apparatus when the cooling I means is in service.

It is my object as hereinbefore'set: forth to' provide a structure in which an'anticipating It is of the double throwt, hag the tt and i t arranged to be simultaneously actuated.

heater can be used in a summer-winter thermostat to perform its function of shortening the operating period when the cooling device is inservice as well as when the heating device is in service.

Other objects have been mentioned and still others will appear from my description and explanation.

A structure by which my purpose can be accompanies is shown in the drawing. in which the to reference numeral Iii indicates a heating means, in which the production of heat or the distribution heat, or both, may be electrically controll The cooler is indicated at H and may be any I type of cooling equipment that may be electrically controlled.

It will be understood that one or a considerable number of rooms may be air conditioned by a system of this kind. 10

I have shown a summer-winter thermostat, having the temperature sensitive member l2, which may be of the bimetallic thermostat type, having'the am it actuated from the member and carrying the contacts are arranged to cooperate respectively with the contacts l6 and II. This is any kind of structure of the snap action or equivalent type. g

The thermostat is subject to the temperature in the room in which the air is to be conditioned.

The contact it engages the contact it for closing the heating circuit, when the thermostat is used for heating service, and the contact it engages the contact til to close the cooling circult.

I provide a ramer-winter switch, which as here she is apted to be manually operated.

k is.

The a it has the contact N, which is arranged to coast with the contact 26. The it has the contact 22 arranged to ct with the contact 28. The it also has the contact 26 to coact with the contact 28'. This switch may be an auas tomatie one. a

The line wire it is eiectricaily connecteoi-by a wire 20 with the contacts it and it as for instance through the member I! andthe arm it.

The contact is is connected by a conducting Mi wire 2! with the anticipating heater 28.

The heater 28 is located to heat the temperature sensitive member. l2, and is connected by a wire I'Ia with the arm l9.

It will be un l4 and II, which 35 erstood that the heater I0 and the I cooler I I are provided with elements arranged to be actuated when included in electric circuits, such as motors or valves or dampers.

The contact 23 is electrically connected to the heater III by the wire 29 and the heater is connected through a wire 30 with the other line wire with the temperature sensitive member 34b. The

member 34b is connected by a wire 31 with the adjustable resistance 35.

The switch A may be of the automatic type as illustrated or may be manually operable. The resistance 35 is connected by a wire 38 to the line wire 39.

The thermostat switch A is subject to the temperature in the room to be air conditioned, but is sufiiciently isolated from the heater 28, so as not to be substantially affected by the heat emanating from the heater.

Operation when heater is in service In the use of this control, if it be assumed that the heater is to be automatically operated in cold weather, the switch arms I8 and I9 are moved to position where the contact 22 engages the contact 23.

Assume that the temperature of the room in which the element I2 is located has dropped to the point, where according to its setting, the thermostat calls for heat.

Contact M. then engages contact I6. A circuit is thus closed from the line wire 40 through the wire 26, thermostatic element I2, arm I3, contacts I4 and I6, wire 21, heater 28, wire 21a, arm I9 contact 22, contact 23, wire 29, heater I0, wire 30 and line wire 39.

The heater I0 then functions.

The combined effect of the rise in room temperature and of the heater 28, on the element I2, results in the separation of the contacts I4 and I 6 and the breaking of. the circuit above described. The heater I0 is thus shut down.

This is the usual operation.

It will be noted that when the circuit is broken, the arm I3 moves to position where the contact I5 engages contact II. No circuit is thereby closed, because of the gap between the contacts 2I and 20 existing by reason of the position of the arms I8 and I9 of the summer-winter switch.

In the operation, the heater 28 aids in raising the temperature of the member I2 while the heater I0 is raising the room temperature.

The effect is to cause the circuit to break earlier than would be the case if the anticipating heater 28 were not used.

These anticipating heaters are used to prevent undesirable overruns and contribute to the maintenance of more even temperature in the room.

Operation when cooler is in service In summer or when it is warm, and it is desired .to'use the cooler, the switch arms I8 and I9 are moved away from their positions shown in the the contact 2I and the contact 24 engages contact 25.

Assume a condition in the room in which the sensitive element I2 is located, that causes the element to call for an operation of the apparatus which it controls (in this case a cooler).

The contact I5 engages the contact II. Thereupon a circuit is closed from the line wire 40, through wire 26, element I2, arm I3, contacts I5 and I1, wire 3|, contacts 2I and 20, arm I8, wire 32, cooler I I, wire 33 and line wire 39.

Thereupon the cooler will function.

When the temperature has been lowered to the point where the element I2 functions to separate contacts I5 and II, the circuit just described is broken and the operation of the cooler ceases.

In the circuit breaking operation, the arm I3 moves the contact l4 into engagement with the contact I6.

By so doing, a circuit is closed during the standbyperiod from the line wire 40 through wire 26,

the

element I2, arm I3, contacts I4 and I6, wire 21,

heater 28, wire 21a, arm I9, contact 24, contact 25, wire 36, contact 36a, contact 34a, arm 34, element 34b, wire 31, adjustable resistance 35, wire 38, and line wire 39.

The effect of closing this circuit is to subject the element I2 to heat from the heater 28, thus anticipating a rise in-"room temperature and causing the thermostatto again call for operation of the cooling equipment earlier than would be the case with a conventional thermostat not equipped with an anticipating heater.

Thus overruns are reduced in amount inboth heating and cooling service.

The efiect of the heater in cooling service may be varied as desired by adjusting the adjustable resistance 35* There may be conditions when it is not desirable or necessary to operate the cooling system. For example, where this system is used to cool a home, the weather may be so cool, that there Is no reason for operating the system.

If, however, under such conditions, a manually operated summer-winter switch has been set for cooling service, then during the stand-by period, a circuit is normally closed through the heater 23, and unless that circuit were broken, the eflect of the heater on the element I2 would result in the unnecessary operation of the cooler.

I have provided means for preventing this unnecessary operation of the cooling system.

The switch A, ii. of the thermostatic type, can be set to automatically hold open the circuit through the heater 28 when conditions do not warrant the operation of the cooling system. If the switch A is of the manually operated type, it serves the same function, and it opened, and then overlooked, will still permit the cooling equipment to function, although it will function without the anticipating feature of the thermostat.

Where the summer-winter switch is 01. the automatic type, the switch A may be omitted in some installations.

I claim as my invention:

1 In a system, having a heating device and a cooling device, electrical control means for the devices including a thermostatic switch and heating means arranged to cooperate with the switch to hasten the movement of the switch when either device is in service, and a change over switch for selectively putting either device in service.

2. In combination, a heating device and a cooling device, electrical control means for the de-' vices including a thermostat, and a summer-winter switch, and anticipating heater means adapted to hasten the action of the thermostat for stopping the operation of a controlled device when the switch is in one position and to hasten the action of the thermostat for starting the opera tion of a controlled device when the switch is in the other position.

3. In combination, a heating device and a cooling device, electrical control means for the devices including a thermostat, and a summer-win- .ter switch, and anticipating heater means adapted to hasten the action of the thermostat for stopping the operation of a controlled device when the switch is in one position, and to hasten the action of the thermostat for starting the operation of a controlled device when the switch is in the other in the other position, and means for automatically rendering the anticipating heater inoperative when certain predetermined conditions exist and the switch is in one of its positions.

is 5. In combination, a' heating device and a cool-' ing device, electrical control means for the deof said anticipating heater and vices including a thermostat, and a summer -winter switch, and anticipating heater means adapted to hasten the action of the thermostat for stopping the operation of a controlled device when the switch is in one position, andto hasten the action of the thermostat for starting the operation of a-controlled device when the switch isin the other position, and means for rendering the anticipating heater inoperative. V

6. In a system having a heating device and a cooling device, control means therefor, including a summer-winter thermostat electrically associated with said, devices, an anticipating heater associated with the thermostat to hasten the action of the thermostat in stopping the operation of the heating device when the heating device is in service, and to hasten the action of the thermostat for starting the operationo'f the cooling device when the cooling device is in service, and a change over switch for selectively putting either device into service.

7. In an air conditioning system, a heating device, a cooling device, a.summer-winter thermostat electrically associated therewith, a switch for selectively including either the heating device or the cooling device in circuit with the thermostat.

an electrical anticipating :heater associated withthe thermostat to function during the heating cycle when the heating device is in service, and during thestandby period when, the cooling device is in service, means for varying the action tive means for rendering the anticipating heater inoperative when certain conditions exist. WILLIAM w. STUART,

condition sensi- 

